delphi 取硬盘号

function GetVolumeID: string;
var
  vVolumeNameBuffer: array[..] of Char;
  vVolumeSerialNumber: DWORD;
  vMaximumComponentLength: DWORD;
  vFileSystemFlags: DWORD;
  vFileSystemNameBuffer: array[..] of Char;
begin
  if GetVolumeInformation('C:\', vVolumeNameBuffer, SizeOf(vVolumeNameBuffer),
    @vVolumeSerialNumber, vMaximumComponentLength, vFileSystemFlags,
    vFileSystemNameBuffer, SizeOf(vFileSystemNameBuffer)) then
  begin
    Result := IntToHex(vVolumeSerialNumber, );
  end;
end;